Humane stunning in the slaughter of wild-caught fish for food

Abstract

This research project will investigate the feasibility of the development and use of humane stunning in the slaughter of commercially caught wild finfish.

Description

An estimated 0.79 to 2.3 trillion wild finfish are caught globally each year. Evidence that fish are sentient and able to experience fear, pain and suffering, has led to international recognition that there is a need to improve the welfare of fish for consumption, including at point of slaughter. 

As a general principal, based on scientific evidence, existing guidelines developed for farmed fish state that fish should be humanely stunned before killing, to ensure immediate and irreversible loss of consciousness, which lasts until death. Where stunning is reversible, fish should be killed before consciousness is recovered. Stunning methods considered humane are: electrical stunning, percussive stunning, spiking and coring and free bullet. The choice of method should take account of species-specific information where available.  

The vast majority of wild-caught fish are not humanely stunned before killing, and evidence suggests these fish may experience significant suffering between the time they are captured and their death. To date guidelines for the humane stunning of wild-caught fish are extremely limited. 

This project will comprise of 3 major components to investigate the overall feasibility of humane stunning in wild-capture fisheries:

Stage 1. An overview of the worldwide wild-capture fishing industry including:  

• Estimates of the tonnage of each species captured and the number of each species captured 
• The method by which those species are captured and killed
• The geographical area where these fish are caught and the market where they are sold 
• The extent to which any of these fish are currently humanely stunned
• Reasons for lack of uptake of stunning 

Stage 2.  A systematic map of published research and grey literature, asking “What is the evidence for humane stunning in the slaughter of wild-caught fish for food?”  The systematic map will provide an overview of the evidence base and will be used to identify knowledge gaps that would benefit from primary research, and sub-sets of evidence that may be suitable for further secondary synthesis. The evidence gathered will address the following questions:

• Is there any evidence of the commercial use of or testing of stunning devices/methods on-board wild-capture fishing vessels? What types of stunning devices/methods have been used or tested on-board for different species of wild-caught fish? Where have these devices/methods been used or tested geographically? 
• What types of stunning methods/devices have been tested for different fish species under laboratory or farmed conditions that are of relevance to wild-capture fisheries? Where have these studies been carried out geographically? What fish welfare outcomes are reported?  
• What evidence is there about the impact of stunning on flesh quality? 
• Is there any evidence about the feasibility or economic viability of the use of stunning for wild-caught fish? 
• Are there any studies or methods that investigate the process between capture and application of stunning method to minimise suffering prior to stunning? 
• Are there any studies about the cost implications of the use of stunning in wild-capture fisheries on product price? 
• Are there any studies on the likelihood of uptake? 
• What other environmental, social, socio-economic, economic or practical implications are reported in studies about stunning in wild-capture fishing? 

Stage 3. A feasibility analysis (using the outputs of stages 1 & 2) of which fishing system, species of fish, geographical fishing area etc is most amenable to the adoption of routine humane stunning of wild-caught fish, considering: where the need is greatest; where uptake is most likely to be feasible; the potential impact on sustainability and any potential synergy between stunning and increased sustainability. 

Acknowledgements: Many thanks to Salvador Prats Aparicio for his work on this research.

The draft protocol has also been published on the Systematic Reviews for Animals and Food  (SYREAF) website.